Smart dialysis bag detection system

ABSTRACT

A dialysis machine (e.g., a peritoneal dialysis (PD) machine) can include a safety feature that enables the dialysis machine to automatically identify the connections made by a user in preparation for treatment. A smart connector is disclosed that uses a split RFID device that is operational when a first portion of the connector is mated to a second portion of the connector, and is not operational when the first portion is disconnected from the second portion. In an embodiment, the split RFID device incorporates an RFID chip in the first portion of the connector and an antenna in the second portion of the connector. In an embodiment, the RFID chip can store a tag that encodes information that indicates a formulation or a volume of a dialysis bag connected to the ports of a disposable cassette such that the dialysis machine can automatically discover the configuration of the dialysis setup.

BACKGROUND

Dialysis is a treatment used to support a patient with insufficientrenal function. The two principal treatment options are hemodialysis(HD) and peritoneal dialysis (PD). During hemodialysis, the patient'sblood is removed, e.g., via an arteriovenous (AV) fistula or othermethods (e.g., AV graft), and passed through a dialyzer of a dialysismachine while also passing a dialysis solution, referred to asdialysate, through the dialyzer. A semi-permeable membrane in thedialyzer separates the blood from the dialysate within the dialyzer andfacilitates the exchange of waste products (e.g., urea, creatine,potassium, etc.) between the blood stream and the dialysate. Themembrane prevents the transfer of blood cells, protein, and otherimportant components in the blood stream from entering the dialysatesolution. The cleaned blood stream is then returned to the patient'sbody. In this way, the dialysis machine functions as an artificialkidney for cleaning the blood in patients with insufficient renalfunction.

In contrast with hemodialysis, the peritoneal dialysis treatment optionintroduces dialysate into a patient's peritoneal cavity, which is anarea in the abdomen between the parietal peritoneum and visceralperitoneum (e.g., a space between the membrane that surrounds theabdominal wall and the membranes that surround the internal organs inthe abdomen). The lining of the patient's peritoneum functions as asemi-permeable membrane that facilitates the exchange of waste productbetween the bloodstream and the dialysate, similar in function to themembrane in the dialyzer of the hemodialysis machine. The patient'speritoneal cavity is drained and filled with new dialysate over a numberof PD cycles. Peritoneal dialysis can be performed using either gravityor an automated pumping mechanism to fill and drain the abdomen during aPD cycle.

Automated PD machines, sometimes referred to as PD cyclers, are designedto control the PD treatment process so that it can be performed at homewithout clinical staff, typically while the patient sleeps overnight soas to minimize interference with the patient's life. The process isreferred to as continuous cycler-assisted peritoneal dialysis (CCPD).Many PD cyclers are designed to automatically infuse, dwell, and draindialysate to and from the peritoneal cavity. The PD treatment typicallylasts several hours, often beginning with an initial drain phase toempty the peritoneal cavity of used or spent dialysate that was left inthe peritoneal cavity at the end of the last PD treatment. The sequencethen proceeds through a progression of fill, dwell, and drain phasesthat follow sequentially. A group of fill, dwell, and drain phases, inorder, can be referred to as a PD cycle.

Sterile dialysate solution is provided to the patient or caregiver in avariety of volumes and compositions. For example, dialysate bags maycommonly be provided in 2 liter (L), 3 L, or 5 L volumes. Dialysatesolution can also be provided in a 1.5% dextrose concentration, a 2.5%dextrose concentration, a 4.25% dextrose concentration, or the like.Furthermore, the solution can include various concentrations of otherelements such as magnesium and/or calcium.

Conventional PD machines typically rely on the patient or caregiver toconnect the bags to the PD machine or disposable cassette. The cassettecan include a number of lines including a plurality of lines connectedto one or more dialysate bags, a heater line bag, a patient line, and adrain line. The PD machine may have limited capability to confirm that apatient has connected a dialysate bag to the correct line (such as bymonitoring a line pressure of each line), but cannot confirm that thepatient or caregiver has connected a dialysate bag with the correctvolume or concentration to said line. Incorrect connections can causeinterruptions in treatment (e.g., where a patient is prompted to replacethe dialysate bag) or could be dangerous to the patient (e.g., couldcause electrolyte imbalance, hypervolemia, or underdialysis). Thus,there is a desire to implement new safety mechanisms that enable the PDmachine to verify the source of dialysate introduced to each lineattached to the PD machine.

SUMMARY

In accordance with one aspect of the disclosure, a dialysis system isprovided that includes a safety feature. The safety feature enables thedialysis system to monitor the formulation and volume of one or moredialysate bags connected to the dialysis system. Each dialysate bag isconnected to a fluid line with one half of a connector attached thereto.The other half of the connector is attached to another fluid lineconnected to the dialysis system or a port of a disposable cassette usedby a peritoneal dialysis machine. When the first half of the connectoris connected to the second half of the connector, fluidly coupling thedialysate bag to the dialysis system, a wireless device in the connectoris enabled, which can then be read by the dialysis machine to identifythe type of dialysate (e.g., the formulation) and a volume of thedialysate connected to the dialysis system.

In an embodiment, the dialysis system includes a wireless interface incommunication with one or more connectors attached to fluid lines, and areader configured to access information stored in the one or moreconnectors. Each connector of the one or more connectors includes afirst portion and a second portion. At least one of the first portion orthe second portion includes a radio frequency identifier (RFID) devicethat is operational when the first portion is mated with the secondportion and is not operational when the first portion is disconnectedfrom the second portion.

In some embodiments, the reader is a near field communication (NFC)device. The NFC device is configured to: transmit a radio frequency (RF)signal over the wireless interface, and receive an RFID signal from afirst connector of the one or more connectors that includes a tag thatindicates at least one of a formulation or a volume of a dialysis bagconnected to a first fluid line fluidly coupled to the first connector.

In some embodiments, the dialysis system further includes a disposablecassette that includes a plurality of ports, each port fluidly coupledto the second portion of a corresponding connector of the one or moreconnectors.

In an embodiment, the second portion includes an antenna of the RFIDdevice and the first portion of the corresponding connector, when matedto the second portion, includes an RFID chip. In another embodiment, thesecond portion includes an interconnect configured to route a signalfrom a first terminal to a second terminal. The first portion of thecorresponding connector, when mated to the second portion, includes anRFID chip and an antenna, and a signal interconnect from the RFID chipis connected to the first terminal and the second terminal is connectedto the antenna.

In yet other embodiments, the second portion includes a memory thatstores second information that identifies the port of the disposablecassette fluidly connected to the corresponding connector. The firstportion of the corresponding connector, when mated to the secondportion, includes an RFID chip or a memory that stores first informationthat indicates at least one of a formulation or a volume of a dialysisbag, and wherein the RFID chip is configured to encode the firstinformation and the second information to generate a tag that istransmitted to the reader.

In some embodiments, the second portion comprises a female connectorthat includes a tapered orifice. The first portion comprises a maleconnector that includes a protrusion that fits in the tapered orifice.The at least one component of the RFID device is encapsulated in thefirst portion in accordance with an overmolding manufacturing process.

In accordance with a second aspect of the present disclosure, a smartconnector for a medical device is disclosed. The smart connectorincludes a first portion that includes a radio frequency identifier(RFID) chip, and a second portion that enables operation of the RFIDchip when mated to the first portion and disables operation of the RFIDchip when disconnected from the first portion.

In some embodiments, the second portion includes an antenna. A radiofrequency (RF) signal received by the antenna causes the RFID chip totransmit, via the antenna, an RFID signal that includes a tag. The tagcomprises one or more bits that encode information corresponding to atleast one of a formulation or a volume of a dialysis bag connected tothe first portion of the smart connector.

In some embodiments, the first portion is a male connector and thesecond portion is a female connector that includes a tapered orifice.

In some embodiments, the first portion further includes an antenna, andwherein an RFID signal generated by the RFID chip is routed through thesecond portion to the antenna.

In some embodiments, the second portion includes a memory that storessecond information that identifies a port of a disposable cassette. Thefirst portion includes the RFID chip or a memory that stores firstinformation that indicates at least one of a formulation or a volume ofa dialysis bag, and wherein the RFID chip is configured to encode thefirst information and the second information to generate a tag.

In accordance with a third aspect of the present disclosure, a methodfor operating a dialysis machine is disclosed. The method includes thesteps of: transmitting, via a wireless interface, a radio frequency (RF)signal, and receiving, via the wireless interface, at least one tagcorresponding to one or more connectors attached to fluid lines. Eachconnector of the one or more connectors includes a first portion and asecond portion, and at least one of the first portion or the secondportion includes a radio frequency identifier (RFID) device that isoperational when the first portion is mated with the second portion andis not operational when the first portion is disconnected from thesecond portion.

In some embodiments, an RFID signal from a first connector of the one ormore connectors includes a tag that indicates at least one of aformulation or a volume of a dialysis bag connected to a first fluidline fluidly coupled with the first connector.

In some embodiments, the steps further include: receiving prescriptioninformation related to treatment of a patient of the dialysis machine;comparing information received from at least one connector of the one ormore connectors to the prescription information to determine whether atleast one of formulation or volume of one or more dialysis bagsconnected to the one or more connectors matches the prescriptioninformation; and initiating a dialysis treatment when the informationmatches the prescription information, or setting an alarm when theinformation does not match the prescription information.

In some embodiments, the steps further include prompting a user toconnect fluid lines to a disposable cassette, and transmitting,periodically, a radio frequency (RF) signal via a wireless interface topoll the one or more connectors to receive tags that indicate when afirst portion of each connector of the one or more connectors is matedto a second portion of the connector.

In some embodiments, a near field communication (NFC) device receivesthe at least one tag from the wireless interface and is configured to:compare the at least one tag to a history of stored tags to determine ifany of the tags in the at least one tag represent newly discoveredconnections.

In accordance with another aspect of the disclosure, a non-transitorycomputer readable storage medium is provided. The computer readablestorage medium stores instructions that, when executed by a processor,causes a dialysis machine to perform steps of the method set forthabove.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a peritoneal dialysis (PD) system, in accordance withsome embodiments.

FIG. 2 is a perspective view of the PD machine and the PD cassette ofthe PD system of FIG. 1, in accordance with some embodiments

FIG. 3 is a perspective view of an open cassette compartment of the PDmachine of FIG. 1, in accordance with some embodiments.

FIG. 4 is an exploded, perspective view of the PD cassette of FIG. 2, inaccordance with some embodiments.

FIG. 5 is a cross-sectional view of the fully assembled PD cassette ofFIG. 2, in accordance with some embodiments.

FIGS. 6 and 7 are perspective views of the PD cassette of FIG. 2 from afront side and a back side, respectively, in accordance with someembodiments.

FIG. 8 illustrates the PD cassette seated against the cassetteinterface, in accordance with some embodiments.

FIG. 9 illustrates a smart connector, in accordance with someembodiments.

FIG. 10 illustrates a schematic of a split RFID device, in accordancewith some embodiments.

FIG. 11 illustrates a schematic of a split RFID device, in accordancewith another embodiment.

FIG. 12 illustrates a schematic of a split RFID device, in accordancewith another embodiment.

FIG. 13 illustrates a system for reading the RFID tag incorporated intothe smart connector, in accordance with an embodiment.

FIG. 14 is a flow diagram of a method for operating a dialysis machine,in accordance with some embodiments.

FIG. 15 is a flow diagram of a method for operating a dialysis machine,in accordance with some embodiments.

FIG. 16 illustrates an exemplary computer system, in accordance withsome embodiments.

FIG. 17 is a schematic illustration showing a dialysis system with whichthe smart dialysis bag detection system described herein may beutilized, according to an implementation of the present disclosure.

DETAILED DESCRIPTION

A dialysis machine, such as a peritoneal dialysis (PD) machine, can bedesigned to include a safety feature. The safety feature enables thedialysis machine to detect the formulation and/or volume of dialysatebags connected to the dialysis machine automatically. In someembodiments, each fluid connector attached to a disposable cassette of aPD machine includes a radio frequency identifier (RFID) device that canbe accessed wirelessly by a reader included in the PD machine. The RFIDdevice is configured such that the circuit and/or components of the RFIDdevice are split between the male and female connectors of the fluidconnector. For example, the female connector attached to the disposablecassette can include an antenna portion of the RFID device and the maleconnector attached to the dialysate bag can include a chip portion ofthe RFID device. The chip portion includes information (e.g., a tag)that can be decoded by the dialysis machine to identify the formulationand/or volume of the dialysate bag.

In some embodiments, the female connector attached to the dialysate bagcan include a memory that stores the information that identifies theformulation and/or volume of the dialysate bag, and the male connectorattached to the disposable cassette can include the chip portion and theantenna portion of the RFID device. The circuit of the RFID device isdesigned in such a manner as to require the chip portion to be connectedto the memory in the female connector in order to function as an RFIDdevice.

In other embodiments, the female connector attached to the dialysate bagcan include the chip portion and the antenna portion of the RFID deviceas well as a memory that stores the information that identifies theformulation and/or volume of the dialysate bag. The male connectorattached to the disposable cassette can also include a memory thatstores information that identifies the port of the disposable cassette,where the information can be combined by the chip portion to generateaggregate information that identifies both the formulation and/or volumeof the dialysate bag and the particular port of the disposable cassetteconnected to the dialysate bag. It will be appreciated that any mannerof splitting the RFID device between the male and female connectors suchthat operation of the RFID device is only enabled when the connection ismade, and storing information that identifies the formulation and/orvolume of the dialysate bag on the connector attached to the dialysatebag, is within the scope of the present disclosure. It will also beappreciated that, in some embodiments, the female connector can beattached to the disposable cassette and the male connector can beattached to the dialysate bag. In such embodiments, the components ineach of the connectors can be swapped, compared to the embodimentsdescribed above.

In some embodiments, the information read from the tag(s) by the readercan be utilized by a controller of the dialysis machine to change theoperation of the dialysis machine. For example, by automaticallydetecting the volume and/or concentration of the dialysate bag connectedto each port of the disposable cassette, the dialysis machine candetermine when a dialysis bag has been drained and switch to a new portto supply a heater bag with clean dialysate solution. As anotherexample, different volumes of dialysate from two different dialysatebags with different concentrations of minerals or electrolytes can bemixed to create concentrations between the two source concentrations(e.g., equal volume of 1.5% dextrose and 2.5% dextrose solutions can bemixed to create a 2.0% dextrose solution, or a 10% dextrose solution canbe mixed with pure saline to produce a concentration between 0-10%).

In an embodiment, the dialysis machine can set an alarm or alert thepatient or caregiver of an issue detected during setup of the machine.For example, the dialysis machine can detect that a dialysis bag isconnected to the wrong port of the disposable cassette and then alertthe patient or caregiver of the mistake. In some embodiments,prescription data related to a treatment plan for a patient can bedownloaded into the dialysis machine. The prescription data can include,e.g., a concentration of the dialysate solution as well as timing foreach PD treatment cycle and a total number of cycles. The dialysismachine can confirm that the dialysate bags attached to the disposablecassette match the prescription information. In another example, giventhat the dialysis machine can read the expected volume of a dialysatebag, any discrepancy between the volume drawn from the dialysate bag andthe expected volume can trigger an alarm that indicates that there couldbe a leak in the system, flow sensors could be malfunctioning, or thelike.

FIG. 1 illustrates a peritoneal dialysis (PD) system 100, in accordancewith some embodiments. The PD system 100 can include a PD machine 102,which can alternately be referred to as a PD cycler, seated on a cart104. The PD machine 102 includes a housing 106, a door 108, and acassette interface 110 that contacts a disposable PD cassette 112 whenthe cassette 112 is disposed within a cassette compartment 114 formedbetween the cassette interface 110 and the closed door 108. The cassettecompartment 114, cassette interface 110, and cassette 112 are shown inmore detail in FIG. 2. A heater tray 116 is positioned on top of thehousing 106. The heater tray 116 is sized and shaped to accommodate abag of PD solution such as dialysate (e.g., a 5 liter bag of dialysate).The PD machine 102 also includes a user interface such as a touch screendisplay 118 and additional control buttons 120 that can be operated by auser (e.g., a caregiver or a patient) to allow, for example, set up,initiation, and/or termination of a PD treatment.

Dialysate bags 122 are suspended from fingers on the sides of the cart104, and a heater bag 124 is positioned in the heater tray 116. Thedialysate bags 122 and the heater bags 124 are connected to the cassette112 via dialysate bag lines 126 and a heater bag line 128, respectively.The dialysate bag lines 126 can be used to pass dialysate from dialysatebags 122 to the cassette 112 during use, and the heater bag line 128 canbe used to pass dialysate back and forth between the cassette 112 andthe heater bag 124 during use. In addition, a patient line 130 and adrain line 132 are connected to the cassette 112. The patient line 130can be connected to a patient's abdomen via a catheter and can be usedto pass dialysate back and forth between the cassette 112 and thepatient's peritoneal cavity during use. The catheter may be surgicallyimplanted in the patient and connected to the patient line 130 via aport, such as a fitting, prior to the PD treatment. The drain line 132can be connected to a drain or drain receptacle and can be used to passdialysate from the cassette 112 to the drain or drain receptacle duringuse.

The PD machine 102 also includes a control unit 139 (e.g., a processor,controller, system-on-chip (SoC), or the like). The control unit 139 canreceive signals from and transmit signals to the touch screen display118, the control panel 120, and the various other components of the PDsystem 100. The control unit 139 can control the operating parameters ofthe PD machine 102. In some embodiments, the control unit 139 includesan MPC823 PowerPC device manufactured by Motorola, Inc. As furtherdiscussed in detail elsewhere herein, in some embodiments, the controlunit 139 may be configured to control disengaging and/or bypassing of apump in connection with naturally draining the dialysate from a patientduring the drain phase of a PD cycle.

FIG. 2 is a perspective view of the PD machine 102 and the PD cassette112 of the PD system 100 of FIG. 1, in accordance with some embodiments.As depicted in FIG. 2, the PD cassette 112 is placed proximate thecassette interface 110. The cassette 112 contains pump chambers 138A,138B, pressure sensing chambers 163A, 163B, and valve chambers forcontrolling the flow of fluid through the cavities of the cassette 112.The cassette 112 is connected to the dialysate bag lines 126, the heaterbag line 128, the patient line 130, and the drain line 132.

The cassette interface 110 includes a surface having holes formedtherein. The PD machine 102 includes pistons 133A, 133B with pistonheads 134A, 134B attached to piston shafts. The piston shafts can beactuated to move the piston heads 133A, 133B axially within pistonaccess ports 136A, 136B formed in the cassette interface 110. Thepistons 133A, 133B are sometimes referred to herein as pumps. In someembodiments, the piston shafts can be connected to stepper motors thatcan be operated to move the pistons 133A, 133B axially inward andoutward such that the piston heads 134A, 134B move axially inward andoutward within the piston access ports 136A, 136B. The stepper motorsdrive lead screws, which move nuts inward and outward on the leadscrews. The stepper motors can be controlled by driver modules. Thenuts, in turn, are connected to the piston shafts, which cause thepiston heads 134A, 134B to move axially inward and outward as thestepper motors drive the lead screws. Stepper motor controllers providethe necessary current to be driven through the windings of the steppermotors to move the pistons 133A, 133B. The polarity of the currentdetermines whether the pistons 133A, 133B are advanced or retracted. Insome embodiments, the stepper motors require 200 steps to make a fullrotation, and this corresponds to 0.048 inches of linear travel of thepiston heads 134A, 134B.

In some embodiments, the PD system 100 also includes encoders (e.g.,optical quadrature encoders) that measure the rotational movement anddirection of the lead screws. The axial positions of the pistons 133A,133B can be determined based on the rotational movement of the leadscrews, as indicated by feedback signals from the encoders. Thus,measurements of the position calculated based on the feedback signalscan be used to track the position of the piston heads 134A, 134B of thepistons 133A, 133B.

When the cassette 112 is positioned within the cassette compartment 114of the PD machine 102 with the door 108 closed, the piston heads 134A,134B of the PD machine 102 align with the pump chambers 138A, 138B ofthe cassette 112 such that the piston heads 134A, 134B can bemechanically connected to dome-shaped fastening members of the cassette112 overlying the pump chambers 138A, 138B. As a result of thisarrangement, movement of the piston heads 134A, 134B toward the cassette112 during treatment can decrease the volume of the pump chambers 138A,138B and force dialysate out of the pump chambers 138A, 138B. Retractionof the piston heads 134A, 134B away from the cassette 112 can increasethe volume of the pump chambers 138A, 138B and cause dialysate to bedrawn into the pump chambers 138A, 138B.

The cassette 112 also includes pressure sensor chambers 163A, 163B. Whenthe cassette 112 is positioned within the cassette compartment 114 ofthe PD machine 102 with the door 108 closed, pressure sensors 151A, 151Balign with the pressure sensor chambers 163A, 163B. Portions of amembrane that overlies the pressure sensor chambers 163A, 163B adhere tothe pressure sensors 151A, 151B using vacuum pressure. Specifically,clearance around the pressure sensors 151A, 151B communicates vacuum tothe portions of the cassette membrane overlying the pressure sensingchambers 163A, 163B to hold those portions of the cassette membranetightly against the pressure sensors 151A, 151B. The pressure of fluidwithin the pressure sensing chambers 163A, 163B causes the portions ofthe cassette membrane overlying the pressure sensor chambers 163A, 163Bto contact and apply a force to the pressure sensors 151A, 151B.

The pressure sensors 151A, 151B can be any sensors that are capable ofmeasuring the fluid pressure in the pressure sensor chambers 163A, 163B.In some embodiments, the pressure sensors are solid state silicondiaphragm infusion pump force/pressure transducers. One example of sucha sensor is the model 1865 force/pressure transducer manufactured bySensym® Foxboro ICT. In some embodiments, the force/pressure transduceris modified to provide increased voltage output. The force/pressuretransducer can, for example, be modified to produce an output signal of0 to 5 volts.

FIG. 3 is a perspective view of an open cassette compartment 114 of thePD machine 102 of FIG. 1, in accordance with some embodiments. Asdiscussed above, the PD machine 102 includes pistons 133A, 133B disposedin piston access ports 136A, 136B, respectively. The PD machine 102 alsoincludes multiple inflatable members 142 positioned within inflatablemember ports 144 in the cassette interface 110. The inflatable members142 align with depressible dome regions of the cassette 112 when thecassette 112 is positioned within the cassette compartment 114 of the PDmachine 102. While only a couple of the inflatable members 142 arelabeled in FIG. 3, it should be understood that the PD machine 102includes an inflatable member 142 associated with each of thedepressible dome regions of the cassette 112. The inflatable members 142act, in cooperation with the depressible dome regions, as valves todirect dialysate through the cassette 112 in a desired manner duringuse. In particular, the inflatable members 142 bulge outward beyond thesurface of the cassette interface 110 and into contact with thedepressible dome regions of the cassette 112 when inflated, and retractinto the inflatable member ports 144 and out of contact with thecassette 112 when deflated. By inflating certain inflatable members 142to depress their associated dome regions on the cassette 112, certainfluid flow paths within the cassette 112 can be occluded. Thus,dialysate can be pumped through the cassette 112 by actuating the pistonheads 134A, 134B, and can be guided along desired flow paths within thecassette 112 by selectively inflating and deflating the variousinflatable members 142.

In some embodiments, locating pins 148 extend from the cassetteinterface 110 of the PD machine 102. When the door 108 is in the openposition, the cassette 112 can be loaded onto the cassette interface 110by positioning the top portion of the cassette 112 under the locatingpins 148 and pushing the bottom portion of the cassette 112 toward thecassette interface 110. The cassette 112 is dimensioned to remainsecurely positioned between the locating pins 148 and a spring loadedlatch 150 extending from the cassette interface 110 to allow the door108 to be closed over the cassette 112. The locating pins 148 help toensure that proper alignment of the cassette 112 within the cassettecompartment 114 is maintained during use.

The door 108 of the PD machine 102 defines cylindrical recesses 152A,152B that substantially align with the pistons 133A, 133B when the door108 is in the closed position. When the cassette 112 is positionedwithin the cassette compartment 114 with the door 108 closed, the pumpchambers 138A, 138B at least partially fit within the recesses 152A,152B. The door 108 further includes a pad that is inflated during use tocompress the cassette 112 between the door 108 and the cassetteinterface 110. With the pad inflated, the portions of the door 108forming the recesses 152A, 152B support the surface of the pump chambers138A, 138B, and the other portions of the door 108 support the otherregions or surfaces of the cassette 112. The door 108 can counteract theforces applied by the inflatable members 142 and, therefore, allows theinflatable members 142 to actuate the depressible dome regions on thecassette 112. The engagement between the door 108 and the cassette 112can also help to hold the cassette 112 in a desired position within thecassette compartment 114 to further ensure that the pistons 133A, 133Balign with the fluid pump chambers 138A, 138B of the cassette 112.

The control unit 139 of FIG. 1 is connected to the pressure sensors151A, 151B, to the stepper motors (e.g., the drivers for the steppermotors) that drive the pistons 133A, 133B, and to the encoders thatmonitor rotation of the lead screws attached to the stepper motors suchthat the control unit 139 can receive signals from and transmit signalsto those components of the PD system 100. The control unit 139 monitorsthe components to which it is connected to determine whether anycomplications exist within the PD system 100, such as the presence of anocclusion or blockage in the patient line 130.

FIG. 4 is an exploded, perspective view of the PD cassette 112 of FIG.2, in accordance with some embodiments. FIG. 5 is a cross-sectional viewof the fully assembled PD cassette 112 of FIG. 2, in accordance withsome embodiments. FIGS. 6 and 7 are perspective views of the PD cassette112 of FIG. 2 from a front side and a back side, respectively, inaccordance with some embodiments.

As depicted in FIGS. 4-7, the PD cassette 112 includes a flexiblemembrane 140 that is attached to a periphery of a tray-like rigid base156. Rigid dome-shaped fastening members 161A, 161B are positionedwithin recessed regions 162A, 162B of the base 156. The dome-shapedfastening members 161A, 161B are sized and shaped to receive the pistonheads 134A, 134B of the PD machine 102. In some embodiments, thedome-shaped fastening members 161A, 161B have a diameter, measured fromthe outer edges of annular flanges 164A, 164B, of about 1.5 inches toabout 2.5 inches (e.g., about 2.0 inches) and take up about two-thirdsto about three-fourths of the area of the recessed regions 162A, 162B.The annular flanges 164A, 164B of the rigid dome-shaped fasteningmembers 161A, 161B are attached in a liquid-tight manner to portions ofthe inner surface of the membrane 140 surrounding substantially circularapertures 166A, 166B formed in the membrane 140. The annular flanges164A, 164B of the rigid dome-shaped fastening members 161A, 161B can,for example, be thermally bonded or adhesively bonded to the membrane140. The apertures 166A, 166B of the membrane 140 expose the rigiddome-shaped fastening members 161A, 161B such that the piston heads134A, 134B are able to directly contact and mechanically connect to thedome-shaped fastening members 161A, 161B during use.

The annular flanges 164A, 164B of the dome-shaped fastening members161A, 161B form annular projections 168A, 168B that extend radiallyinward and annular projections 176A, 176B that extend radially outwardfrom the side walls of the dome-shaped fastening members 161A, 161B.When the piston heads 134A, 134B are mechanically connected to thedome-shaped fastening members 161A, 161B, the radially inwardprojections 168A, 168B engage the rear angled surfaces of the slidinglatches 145A, 147A of the piston heads 134A, 134B to firmly secure thedome-shaped fastening members 161A, 161B to the piston heads 134A,1334B. Because the membrane 140 is attached to the dome-shaped fasteningmembers 161A, 161B, movement of the dome-shaped fastening members 161A,161B into and out of the base 156 (e.g., due to reciprocating motion ofthe pistons 133A, 133B) causes the flexible membrane 140 to similarly bemoved into and out of the recessed regions 162A, 162B of the base 156.This movement allows fluid to be forced out of and drawn into the fluidpump chambers 138A, 138B, which are formed between the recessed regions162A, 162B of the base 156 and the portions of the dome-shaped fasteningmembers 161A, 161B and membrane 140 that overlie those recessed regions162A, 162B.

Raised ridges 167 extend from the substantially planar surface of thebase 156 towards and into contact with the inner surface of the flexiblemembrane 140 when the cassette 112 is compressed between the door 108and the cassette interface 110 of the PD machine 102 to form a series offluid passageways 158 and to form the multiple, depressible dome regions146, which are widened portions (e.g., substantially circular widenedportions) of the fluid pathways 158, as shown in FIG. 6. The fluidpassageways 158 fluidly connect the fluid line connectors 160 of thecassette 112, which act as inlet/outlet ports of the cassette 112, tothe fluid pump chambers 138A, 138B. As noted above, the variousinflatable members 142 of the PD machine 102 act on the cassette 112during use. The dialysate flows to and from the pump chambers 138A, 138Bthrough the fluid pathways 158 and dome regions 146. At each depressibledome region 146, the membrane 140 can be deflected to contact the planarsurface of the base 156 from which the raised ridges 167 extend. Suchcontact can substantially impede (e.g., prevent) the flow of dialysatealong the region of the pathway 158 associated with that dome region146. Thus, the flow of the dialysate through the cassette 112 can becontrolled through the selective depression of the depressible domeregions 146 by selectively inflating the inflatable members 142 of thePD machine 102.

The fluid line connectors 160 are positioned along the bottom edge ofthe cassette 112. As noted above, the fluid pathways 158 in the cassette112 lead from the pumping chambers 138A, 138B to the various connectors160. The connectors 160 are positioned asymmetrically along the width ofthe cassette 112. The asymmetrical positioning of the connectors 160helps to ensure that the cassette 112 will be properly positioned in thecassette compartment 114 with the membrane 140 of the cassette 112facing the cassette interface 110. The connectors 160 are configured toreceive fittings on the ends of the dialysate bag lines 126, the heaterbag line 128, the patient line 130, and the drain line 132. One end ofthe fitting can be inserted into and bonded to its respective line andthe other end can be inserted into and bonded to its associatedconnector 160. By permitting the dialysate bag lines 126, the heater bagline 128, the patient line 130, and the drain line 132 to be connectedto the cassette 112, as depicted in FIGS. 1 & 2, the connectors 160allow dialysate to flow into and out of the cassette 112 during use. Asthe pistons 133A, 133B are reciprocated, the inflatable members 142 canbe selectively inflated to allow fluid to flow from any of the lines126, 128, 130, and 132 to any of ports 185A, 185B, 187A, and 187B of thepump chambers 138A, 138B or to allow fluid to flow from any of ports185A, 185B, 187A, and 187B of the pump chambers 138A, 138B to any of thelines 126, 128, 130, and 132.

The rigidity of the base 156 helps to hold the cassette 112 in placewithin the cassette compartment 114 of the PD machine 102 and to preventthe base 156 from flexing and deforming in response to forces applied tothe projections 154A, 154B by the dome-shaped fastening members 161A,161B and in response to forces applied to the planar surface of the base156 by the inflatable members 142. The dome-shaped fastening members161A, 161B are also sufficiently rigid that they do not deform as aresult of usual pressures that occur in the pump chambers 138A, 138Bduring the fluid pumping process. Thus, the deformation or bulging ofthe annular portions 149A, 149B of the membrane 140 can be assumed to bethe only factor other than the movement of the pistons 133A, 133B thataffects the volume of the pump chambers 138A, 138B during the pumpingprocess.

The base 156 and the dome-shaped fastening members 161A, 161B of thecassette 112 can be formed of any of various relatively rigid materials.In some embodiments, these components of the cassette 112 are formed ofone or more polymers, such as polypropylene, polyvinyl chloride,polycarbonate, polysulfone, and other medical grade plastic materials.In some embodiments, these components can be formed of one or moremetals or alloys, such as stainless steel. These components canalternatively be formed of various different combinations of theabove-noted polymers and/or metals/alloys. These components of thecassette 112 can be formed using any of various different techniques,including machining, molding, and casting techniques.

As noted above, the membrane 140 is attached to the periphery of thebase 156 and to the annular flanges 164A, 164B of the dome-shapedfastening members 161A, 161B. The portions of the membrane 140 overlyingthe remaining portions of the base 156 are typically not attached to thebase 156. Rather, these portions of the membrane 140 sit loosely atopthe raised ridges 165A, 165B, and 167 extending from the planar surfaceof the base 156. Any of various attachment techniques, such as adhesivebonding and thermal bonding, can be used to attach the membrane 140 tothe periphery of the base 156 and to the dome-shaped fastening members161A, 161B. The thickness and material(s) of the membrane 140 areselected so that the membrane 140 has sufficient flexibility to flextoward the base 156 in response to the force applied to the membrane 140by the inflatable members 142. In some embodiments, the membrane 140 isabout 0.100 micron to about 0.150 micron in thickness. However, variousother thicknesses may be sufficient depending on the type of materialused to form the membrane 140. Any of various different materials thatpermit the membrane 140 to deflect in response to movement of theinflatable members 142 without tearing can be used to form the membrane140. In some embodiments, the membrane 140 includes a three-layerlaminate. In some embodiments, inner and outer layers of the laminateare formed of a compound that is made up of 60 percent Septon® 8004thermoplastic rubber (i.e., hydrogenated styenic block copolymer) and 40percent ethylene, and a middle layer is formed of a compound that ismade up of 25 percent Tuftec® H1062 (SEBS: hydrogenated styrenicthermoplastic elastomer), 40 percent Engage® 8003 polyolefin elastomer(ethylene octane copolymer), and 35 percent Septon® 8004 thermoplasticrubber (i.e., hydrogenated styrenic block copolymer). The membrane 140can alternatively include more or fewer layers and/or can be formed ofdifferent materials.

FIG. 8 illustrates the PD cassette 112 seated against the cassetteinterface 110, in accordance with some embodiments. As depicted in FIG.8, before starting a PD treatment, the door 108 of the PD machine 102 isopened to expose the cassette interface 110, and the cassette 112 ispositioned with the dome-shaped fastening members 161A, 161B alignedwith the pistons 133A, 133B of the PD machine 102, the pressure sensingchambers 163A, 163B aligned with the pressure sensors 151A, 151B of thePD machine 102, the depressible dome regions 146 aligned with theinflatable members 142 of the PD machine 102, and the membrane 140adjacent to the cassette interface 110. In order to ensure that thecassette 112 is properly positioned on the cassette interface 110, thecassette 112 is positioned between the locating pins 148 and the springloaded latch 150 extending from the cassette interface 110. Theasymmetrically positioned connectors 160 of the cassette 112 act as akeying feature that reduces the likelihood that the cassette 112 will beinstalled with the membrane 140 and dome-shaped fastening members 161A,161B facing in the wrong direction (e.g., facing outward toward the door108). Additionally or alternatively, the locating pins 148 can bedimensioned to be less than the maximum protrusion of the projections154A, 154B such that the cassette 112 cannot contact the locating pins148 if the membrane 140 is facing outward towards the door 108. Thepistons 133A, 133B are typically retracted into the piston access ports136A, 136B during installation of the cassette 112 to avoid interferencebetween pistons 133A, 133B and the dome-shaped fastening members 161A,161B and, therefore, increase the ease with which the cassette 112 canbe positioned within the cassette compartment 114.

After positioning the cassette 112 as desired on the cassette interface110, the door 108 is closed and the inflatable pad within the door 108is inflated to compress the cassette 112 between the inflatable pad andthe cassette interface 110. The compression of the cassette 112 holdsthe projections 154A, 154B of the cassette 112 in the recesses 152A,152B of the door 108 and presses the membrane 140 tightly against theraised ridges 167 extending from the planar surface of the rigid base156 to form the enclosed fluid pathways 158 and dome regions 146. Thepatient line 130 is then connected to a patient's abdomen via acatheter, and the drain line 132 is connected to a drain or drainreceptacle. In addition, the heater bag line 128 is connected to theheater bag 124, and the dialysate bag lines 126 are connected to thedialysate bags 122. At this point, the pistons 133A, 133B can be coupledto the dome-shaped fastening members 161A, 161B of the cassette 112 topermit priming of the cassette 112 and one or more of the lines 126,128, 130, and 132. Once these components have been primed, the PDtreatment can be initiated.

Smart Connectors

FIG. 9 illustrates a smart connector 900, in accordance with someembodiments. The smart connector 900 includes a first portion 910 thatmates with a second portion 920. The first portion 910 and the secondportion 920 include orifices that promote fluid flow across the smartconnector 900. In an embodiment, the first portion 910 is a maleconnector that is connected on a first end to a distensible tube that ispart of or otherwise connected to a dialysate bag line 126. The secondportion 920 is a female connector that is connected on a first end to adistensible tube to form a fluid connector 160 that is part of thedisposable cassette 112. The second end of the male connector includes athreaded port, and the second end of the female connector is configuredto screw into the threaded port. A tapered surface of the orifice in thefemale connector mates with a protruding structure (e.g., a hollowcylinder) formed inside the threaded port of the male connector suchthat, when the male connector is mated with (e.g., screwed into) thefemale connector, the protruding structure is forced into the taperedorifice to form a seal. In some embodiments, the first portion 910 andthe second portion 920 conform with a Leur-Lok™ standard (e.g., ISO8637, ISO 594, ISO 80369, etc.) that defines threaded or unthreadedconnectors that include a tapered fitting. It will be appreciated thatany type of mating connector can be utilized as a smart connector 900and that the present disclosure is not limited to existing medicaldevice fittings such as common Leur-Lok™ fittings. Any fluid connectorthat includes two mated parts is within the scope of the presentdisclosure.

Unlike conventional connectors, the smart connector 900 includes a radiofrequency identifier (RFID) device. The RFID device is split between thefirst portion 910 and the second portion 920 such that the RFID deviceis only active (e.g., operational) when the first portion 910 is matedto the second portion 920. In some embodiments, the RFID devicecomprises a first component 932 and a second component 934 that are inelectrical communication via one or more interconnects 936. It will beappreciated that the smart connector 900 is usually formed by injectinga polymer (e.g., cyclic olefin polymer (COP)) into a mold. In someembodiments, the components of the RFID device can be incorporated intothe connectors 910/920 via an overmolding manufacturing process. Inother words, the components of the RFID device can be placed inside amold prior to the polymer being injected into the mold such that theRFID device is encapsulated within the hardened polymer that forms theparts of the smart connector 900.

In an embodiment, the first component 932 can include a chip (e.g.,integrated circuit, printed circuit, etc.) and the second component 934can include an antenna. The RFID device is not operational withoutforming a circuit that includes both the chip and the antenna. In anembodiment, the RFID device is referred to as a passive device, whichmeans that the RFID device receives power from a radio frequency signalprovided by a reader device (i.e., the RFID chip operates using powerfrom the electrical signal received via the antenna). In otherembodiments, the RFID device can be an active device, which means that aseparate power source is included in one of the parts of the connector900 and used to power the chip. Importantly, the chip is unable toreceive or transmit RF signals without being connected to the antenna,and the antenna cannot produce valid RF signals containing formattedinformation without the chip.

The interconnects 936 are formed from a conducting material such ascopper or other metallic wires or sheet metal. Although not shownexplicitly, the internal surface of the threaded port of the maleconnector and the external surface of the threaded portion of the femaleconnector can include terminals (e.g., metal contacts/pads) formedthereon. In some embodiments, the terminals can include a spring orcantilevered metal strip that allows for a certain amount of clearancebetween the first connector 910 and the second connector 920 while stillmaintaining electrical contact when the first connector 910 is mated tothe second connector 920. In some embodiments, the terminals comprise anannular metallic ring that is molded into the parts 910/920 proximatethe threads, prior to the threads being formed. Subsequent to themolding process, the threads are cut into the polymer and metallic ringssimultaneously to form the contacts such that, when properly seated, aring in the male connector overlaps with a corresponding ring in thefemale connector to form the electrical connection. It will beappreciated that any technically feasible manner for forming contacts tomake an electrical connection when the first portion 910 is mated to thesecond portion 920 is within the scope of the present disclosure.

FIG. 10 illustrates a schematic of a split RFID device 1000, inaccordance with some embodiments. The split RFID device 1000 includes anRFID chip 1010 in a first portion of the connector, such as the firstportion 910 of the smart connector 900, and an antenna 1020 in a secondportion of the connector, such as the second portion 920 of the smartconnector 900. Electrical signals are passed between the RFID chip 1010and the antenna 1020 via one or more terminals 1032/1034. As shown inFIG. 10, two terminals are provided between the RFID chip 1010 and theantenna 1020. However, in other embodiments, three or more terminals maybe provided between the RFID chip 1010 and the antenna 1020. In suchembodiments, the antenna can include more than the conductors for thephysical antenna, but can also include additional components such as achip that includes one or more filters (e.g., bandpass filters), amemory that includes an identifier of the port on the disposablecassette, or the like. Any number of terminals can be provided in thephysical interface between the connectors, assuming that the terminalsare sufficiently isolated electrically and can be formed into theconnectors.

Although not shown explicitly, the RFID chip can include or otherwise beconnected to a memory internal to the first portion 910. The memory caninclude information that specifies the type of dialysate included in thebag connected to the dialysate bag line 126 that is attached to thesecond end of the first portion 910 of the connector 900. For example,the information can include a number of bits (e.g., 4 bits) that canspecify an index (e.g., 0-15) for each of a number of configurations.Table 1, shown below, provides an example of the types of dialysate bagsthat can be identified with 3-bits of information:

TABLE 1 Description Index 1.5% Dextrose, 5L  0 1.5% Dextrose, 6L  1 2.5%Dextrose, 5L  2 2.5% Dextrose, 6L  3 1.5% Dextrose, Low Mg/Ca, 2L  41.5% Dextrose, Low Mg/Ca, 3L  5 1.5% Dextrose, Low Mg/Ca, 5L  6 1.5%Dextrose, Low Mg/Ca, 6L  7 2.5% Dextrose, Low Mg/Ca, 2L/3L  8 2.5%Dextrose, Low Mg/Ca, 3L  9 2.5% Dextrose, Low Mg/Ca, 5L 10 2.5%Dextrose, Low Mg/Ca, 6L 11 4.25% Dextrose, Low Mg/Ca, 2L/3L 12 4.25%Dextrose, Low Mg/Ca, 3L 13 4.25% Dextrose, Low Mg/Ca, 5L 14 4.25%Dextrose, Low Mg/Ca, 5L 15

Table 1 shows that five different types of dialysate solution, in up to5 different volumes, can be coded into a 4-bit code represented by theindices 0-15. Alternative, the information can be split into two 3-bitcodes, where a first code represents the type of dialysate solution inthe bag and a second code represents the volume of the dialysate bag. Itwill also be understood that the codes used to transmit the informationwithin an RFID signal (referred to as a tag) are not limited to 4 or 6bits, and that any number of bits capable of being stored in the RFIDchip and transmitted within the RFID signal can be mapped to differentconfigurations of dialysate solution. In other cases, the RFID signalincludes enough bandwidth to transmit a clear text descriptor for theformulation and/or volume of the dialysate bag, where the descriptorincludes up to a specified number of characters. While using a cleartext descriptor can require a much larger number of bits (e.g., one byteper character), such embodiments are possible if the RFID signal hassufficient bandwidth to transmit that amount of information and thememory included in the RFID chip is sufficient to store the descriptor.

FIG. 11 illustrates a schematic of a split RFID device 1100, inaccordance with another embodiment. It will be appreciated that theimportant aspect of the split RFID device 1000 is that the passive RFIDdevice is only active once the first portion 910 and the second portion920 are mated. While separating the RFID chip 1010 and the antenna 1020is one method for achieving that goal, other configurations of the RFIDdevice that split the components between the first portion 910 and thesecond portion 920 are within the scope of the present disclosure.

In an embodiment, the RFID device 1100 includes both the RFID chip 1010and the antenna 1020 in the first portion 910 of the connector 900.While the major components of the RFID device 1100 are both included inthe same portion of the connector 900, the interconnect for routing theRFID signal to the antenna is routed through the terminals 1032/1034 andthe second portion 920 of the connector 900. For example, a ground planeof the antenna 1020 can be connected to a ground plane of the RFID chip1010 without routing the interconnect between the ground planes out ofthe first portion 910 of the connector 900. Only the interconnect forthe RFID signal is routed from the RFID chip 1010 to a first terminal1032 in the first portion 910, the RFID signal is routed from the firstterminal 1032 to the second terminal 1034 in the second portion 920, andthe RFID signal is routed from the second terminal 1034 to the antenna1020 in the first portion 910, which is used to transmit the RFID signalto a reader via the wireless interface.

It will be appreciated that because the RFID chip 1010 is located in thefirst portion 910 of the connector 900 (i.e., attached to the dialysatebag), the memory storing the information that can be used to encode theidentification of the dialysate bag formulation and/or volume can bestored directly in a memory of the RFID chip 1010. Further, in otherembodiments, the memory storing the information can be separate from theRFID chip 1010 (but still included in the first portion 910 of theconnector 900).

FIG. 12 illustrates a schematic of a split RFID device 1200, inaccordance with another embodiment. With an embodiment like the RFIDdevice 1100, there are no components of the RFID device 1100, other thanthe interconnect for the path of the RFID signal to the antenna 1020, inthe second portion 920 of the connector 900 that is attached to thedisposable cassette 112. Consequently, there is no way for the PDmachine 102 to determine, directly from the RFID signal, which port ofthe cassette 112 the dialysate bag is connected to when the patient orcaregiver connects the dialysate bag line 126 to the cassette 112 bymating the first portion 910 with the second portion 920 of theconnector 900. It will be appreciated that, in some configurations ofthe cassette 112 and PD machine 102, connecting the dialysate bag line126 to the fluid connector 160 of the cassette 112 can allow fluid toflow from the dialysate bag into the cassette 112, where a separatesensor can detect fluid flow or fluid pressure in a chamber of thecassette 112. The PD machine 102 can then infer which port of thecassette 112 the dialysate bag was just connected to, based on thetransitions of the sensor signals. However, such sensing only providesan indirect measurement for detecting which port that a dialysate bagwas connected to when an RFID signal is received after a first portion910 is mated to a second portion 920 of the connector 900. Furthermore,depending on the configuration of the cassette 112 and the sensorsincluded in the PD machine 102, the PD machine 102 may not be capable ofdifferentiating between multiple different dialysate bag lines based onan indirect measurement of a sensor signal having a different primarypurpose. In such cases, it may be beneficial to provide information onboth the formulation and/or volume of the dialysate bag as well as anindication of the particular port of the cassette 112 that the dialysatebag was connected to within the RFID signal (i.e., the tag) itself.

In a split RFID device 1200, first information for identifying theformulation and/or volume of the dialysate bag can be stored in thefirst portion 910 of the connector 900 and second information foridentifying the particular port of the cassette 112 can be stored in thesecond portion 920 of the connector 900. The RFID chip 1010 can thenread the first information from a memory included in the first portion910 and read the second information from a memory included in the secondportion 920 to generate combined information that is encoded into theRFID signal.

As shown in FIG. 12, the RFID chip 1010 and the antenna 1020 can beincluded in the first portion 910 and a memory (e.g., a line memory1210) is included in the second portion 920. The first information canbe stored directly in the RFID chip 1010 and the second information isstored in the line memory 1210. It will be appreciated that, based onthe connection of the RFID chip 1010 and the antenna 1020, the RFID chip1010 and antenna 1020 could be operational (i.e., capable of generatingan RFID signal over the wireless interface) without the line memory 1210and without the first portion 910 being mated with the second portion920. In this embodiment, the RFID chip 1010 should be designed totransmit an RFID signal via the antenna 1020 only when the RFID chip canaccess the line memory 1210, which ensures that the RFID device 1200 isonly operational when the first portion 910 is mated to the secondportion 920, via the use of software or fixed function hardware (i.e.,logic circuits) implemented by the RFID chip 1010. In other words, whilethe circuit theoretically allows the RFID chip 1010 and the antenna 1020to function without being connected to the second portion 920 of theconnector 900, the logic implemented by the RFID chip 1010 prevents theRFID chip 1010 from sending a response to the reader unless the linememory 1210 is detected as being connected to the RFID chip 1010.

In other embodiments, the circuit of FIG. 12 can be modified to routethe interconnect between the RFID chip 1010 and the antenna 1020 throughthe second portion 920, similar to the configuration shown in FIG. 11.This would require two additional terminals in addition to the twoterminals included to route the second information from the line memory1210 to the RFID chip 1010. However, such a modification would simplifythe design of the logic of the RFID chip 1010 as functionality of theRFID tag 1200 would ensure that the first portion 910 was properly matedwith the second portion 920, rather than relying on software or logicdesigned into a fixed function circuit to enable or disable the RFIDdevice 1200.

It will be appreciated that there are many different options for ways tosplit the components of the RFID tag across a connection interface ofthe smart connector 900. However, the component that stores theinformation about the dialysate bag (e.g., formulation/volume) must beincluded in the side of the connector attached to the dialysate bagbecause the disposable cassette 112 is a separate component of thecombined fluid pathway through the PD machine 102. In other words, theminimum requirement of the smart connector 900 is that the portion ofthe connector permanently attached to a dialysate bag, whether thatportion is a male connector or a female connector, includes the storedinformation related to the dialysis bag that is transmitted over thewireless signal to a reader. That information can be stored in adedicated memory separate from the RFID chip or within the RFID chipitself, and the RFID chip can be included separate from or integratedwith the antenna, but at least one component required to make the RFIDtag operation must be located on each side of the smart connectorinterface. For example, in some embodiments, the RFID chip and antennacan be included in the portion of the connector attached to the cassette112, but in such embodiments the RFID chip must be able to access amemory in the portion of the connector attached to the dialysate bagthat stores the information about the dialysate bag.

FIG. 13 illustrates a system 1300 for reading the RFID tag incorporatedinto the smart connector 900, in accordance with an embodiment. Thesystem 1300 includes the smart connector 900 and a near fieldcommunication (NFC) device 1310. The NFC device 1310 can be included inthe PD machine 102 and is configured to communicate with the RFID chip1010 in the smart connector 900 via a wireless interface 1350. As usedherein, the wireless interface can be implemented by a transceiver(e.g., receiver/transmitter) and antenna 1320 connected to the NFCdevice 1310. The antenna 1320 is used to send and receive RF signals viathe wireless interface 1350 to the antenna 1020 of the smart connector900.

In an embodiment, the NFC device 1310 can be designed to operate in afrequency band at 13.56 MHz, with a 14 kHz bandwidth. The NFC device1310 can be referred to as a reader or an NFC reader. The NFC device1310 transmits a RF signal over the wireless interface 1350. If thefirst portion 910 is mated to the second portion 920 of the smartconnector 900, then the antenna 1020 receives the RF signal, whichprovides power to the RFID chip 1010. The RFID chip 1010 operates togenerate an RFID signal that is transmitted back to the NFC device 1310via the antenna 1020, where the RFID signal includes information thatidentifies the dialysate bag attached to the first portion 910 of thesmart connector 900 and, optionally, additional information thatidentifies the specific port on the disposable cassette 112 connected tothe second portion 920 of the smart connector 900.

In other embodiments, the NFC device 1310 can be replaced with a readerthat operates in a different frequency band, such as using a lowfrequency signal (e.g., between 30 kHz and 300 kHz), a high frequencysignal (e.g., between 3 MHz and 30 MHz), or an ultra-high frequencysignal (e.g., between 300 MHz and 3 GHz). Higher frequency signalsgenerally have a lower range compared with lower frequency signals.However, given that the reader is generally incorporated into the PDmachine 102 and will be proximate the smart connector 900, readers inthe high frequency range (e.g., NFC at 13.56 MHz) or ultra-highfrequency (UHF) range may be optimally selected for use in the PDmachine 102.

In an embodiment, the NFC device 1310 is connected to the control unit139 of the PD machine 102. The control unit 139 can be configured toprompt the user (e.g., patient or caregiver) to connect a dialysate bagto the cassette 112 prior to beginning a PD treatment. The control unit139 sends a signal to the NFC device 1310 to monitor the wirelessinterface 1350 to detect the connection of a smart connector 900. In anembodiment, the NFC device 1310 is configured to periodically (e.g.,every 3 seconds) transmit a RF signal over the wireless interface 1350to attempt to detect a new connection. A new connection is detected whenthe NFC device 1310 receives a response from the RFID chip 1010 includedin the smart connector 900. It will be appreciated that multipledialysate bags can be connected to the cassette 112 simultaneously and,therefore, multiple RFID chips from multiple smart connectors 900attached to the cassette 112 can respond to the RF signal broadcast bythe NFC device 1310. In an embodiment, the NFC device 1310 is configuredto collect information from each RFID chip that responds to the RFsignal and store a history of RFID tags corresponding to dialysate bagscurrently connected to the cassette 112. For each RFID tag received bythe NFC device 1310, the NFC device 1310 compares the receivedinformation (e.g., the tag) to stored tags in the history to determineif the tag is associated with a new connection. If the tag is associatedwith a new connection, then the NFC device 1310 can store the tag in thehistory and notify the control unit 139 of the detection of a newconnection as well as provide the control unit 139 with the informationencoded in the tag.

In addition, if the NFC device 1310 fails to receive a response from anRFID chip corresponding to any tag stored in the history for a period oftime (e.g., a time corresponding to one or more RF signals transmittedby the NFC device 1310), then the NFC device 1310 can delete that tagfrom the history to indicate that the corresponding RFID chip has beendisconnected from the cassette 112 (i.e., the male connector for thecorresponding dialysate bag was disconnected from the female connectorof the cassette 112). Consequently, the next time the NFC device 1310receives that tag in a response to the RF signal, the NFC device 1310will detect that the tag is a new connection.

FIG. 14 is a flow diagram of a method 1400 for operating a dialysismachine, in accordance with some embodiments. It will be appreciatedthat the method 1400 is described as being performed by the PD machine102. More specifically, the various steps described below can beimplemented by a processor, such as the control unit 139 of the PDmachine 102, configured to execute a number of instructions. In variousembodiments, the method 1400 can be implemented using hardware, softwareexecuted by a general purpose processor configured to control aspecialized apparatus such as a PD machine, or a combination of hardwareand software.

At step 1402, a user is prompted to connect dialysate (e.g., dialysatebags) to a dialysis machine. In an embodiment, the PD machine 102displays a message on a touchscreen that asks a user to connect adialysate bag to the cassette 112. If more than one dialysate bag isconnected to the cassette 112, then the prompt can indicate theformulation and/or volume of the dialysate bag to connect as well aswhich port of a plurality of ports of the cassette 112 on which toconnect the dialysate bag. In some embodiments, the prompt can beprovided via an audio message instead of or in addition to a visualindication. In other embodiments, step 1402 can be omitted, assumingthat the patient or caregiver has been provided instructions for what toconnect by their doctor or a pharmacist.

At step 1404, the dialysis machine periodically transmit an RF signalover a wireless interface. The RF signal can be a request to one or moreRFID devices within range of the dialysis machine to transmit an RFIDsignal including a tag to the dialysis machine. In an embodiment, the RFsignal can be formatted according to a standard for RFID devices, suchas a standard for NFC tags.

At step 1406, the dialysis machine receives, via the wireless interface,at least one tag corresponding to the one or more connectors. In anembodiment, when a user mates a first portion of a smart connectorattached to a dialysate bag to a second portion of the smart connectorattached to a port of the cassette, the RFID device split across the twoportions of the smart connector is enabled (e.g., operational) and isconfigured to respond to the RF signal transmitted by the dialysismachine by transmitting the RFID signal that includes a tag stored inthe RFID device. In an embodiment, the tag can include first informationthat identifies at least one of the formulation of a dialysate bag aswell as a volume of the dialysate solution included in the dialysatebag. The tag can also optionally include second information thatindicates the port of the cassette connected to the second portion ofthe smart connector.

Optionally, steps 1404 and 1406 can be repeated until a set number ofconnectors have responded to the RF signal, indicating an expectednumber of connections have been made by the user (e.g., patient or caregiver). For example, if two dialysate bags are expected to be connected,the dialysis machine can periodically re-transmit the RF signal over thewireless interface until receiving at least two separate tags from thetwo connectors attached to the two separate dialysis bags. In someembodiments, connectors for other lines, such as the patient line, aheater bag line, and/or a drain line can also be confirmed to have beenconnected based on separate tags returned by corresponding RFID devicesin those connectors.

At step 1408, the dialysis machine initiates a treatment cycle by, e.g.,operating the dialysate machine in accordance with the informationreceived from the smart connectors. For example, the number of treatmentcycles can be paused when the amount of dialysate drained from adialysate bag exceeds an amount calculated by the machine based on thetag information received through a tag. In another example, the dialysismachine can select a source of dialysate based on the detectedconnections.

FIG. 15 is a flow diagram of a method 1500 for operating a dialysismachine, in accordance with some embodiments. It will be appreciatedthat the method 1500 is described as being performed by the PD machine102. More specifically, the various steps described below can beimplemented by a processor, such as the control unit 139 of the PDmachine 102, configured to execute a number of instructions. In variousembodiments, the method 1500 can be implemented using hardware, softwareexecuted by a general purpose processor configured to control aspecialized apparatus such as a PD machine, or a combination of hardwareand software.

At step 1502, a dialysis machine receives prescription information. Inan embodiment, the prescription information can be stored in a USBdevice that is plugged into a USB port of the dialysis machine. Inanother embodiment, the prescription information can be sent to thedialysis machine over a network, such as transmitted to the PD machine102 over a network such as the Internet via a wireless connection. Theprescription information can indicate the type and amount of dialysateprovided to the patient for use in a treatment.

At step 1504, information received from one or more connectors iscompared against the prescription information. In an embodiment, theinformation received from the one or more connectors includes tags fromeach connector that indicates at least one of the formulation and/orvolume of the dialysate bags connected to the dialysis machine.

If the information indicates that the dialysate bags connected to thedialysis machine do not match the expected configuration indicated bythe prescription information, then, at step 1506, the dialysis machinecan set an alarm indicating that the dialysate bags may not be of thecorrect type and/or have sufficient volume to complete the prescribedtreatment. However, if the information matches the prescriptioninformation or the user changes the connections to match theprescription information in response to the alarm, then, at step 1508,the dialysis machine can initiate a treatment cycle.

It will be appreciated that the dialysis machine, by having the abilityto automatically read the information identifying the dialysate bagsconnected to the dialysis machine, can perform safety checks againstprovided prescription information to ensure that the treatment beingadministered is the intended treatment that was prescribed by thepatient's doctor. Such operation can help to prevent unsafe practicesthat result from user error.

FIG. 16 illustrates an exemplary computer system 1600, in accordancewith some embodiments. It will be appreciated that, in variousembodiments, the control unit 139 can be implemented, at least in part,to include the components of the computer system 1600. The processor1610 can execute instructions that cause the computer system 1600 toimplement the functionality of the control unit 139, as described above.

As depicted in FIG. 16, the system 1600 includes a processor 1610, avolatile memory 1620, a non-volatile storage 1630, and one or moreinput/output (I/O) devices 1640. Each of the components 1610, 1620,1630, and 1640 can be interconnected, for example, using a system bus1650 to enable communications between the components. The processor 1610is capable of processing instructions for execution within the system1600. The processor 1610 can be a single-threaded processor, amulti-threaded processor, a vector processor that implements asingle-instruction, multiple data (SIMD) architecture, a quantumprocessor, or the like. The processor 1610 is capable of processinginstruction stored in the volatile memory 1620. In some embodiments, thevolatile memory 1620 is a dynamic random access memory (DRAM). Theinstructions can be loaded into the volatile memory 1620 from thenon-volatile storage 1630. In some embodiments, the non-volatile storage1630 can comprise a flash memory such as an EEPROM. In otherembodiments, the non-volatile storage 1630 can comprise a hard diskdrive (HDD), solid state drive (SSD), or other types of non-volatilemedia. The processor 1610 is configured to execute the instructions,which cause the PD machine 102 to carry out the various functionalitydescribed above.

In some embodiments, the memory 1620 stores information for operation ofthe PD machine 102. For example, the operating parameters can be storedin the memory 1620. The processor 1610 can read the values of theoperating parameters from the memory 1620 and then adjust the operationof the PD machine 102 accordingly. For example, a speed of the pistons133A, 133B can be stored in or written to the memory 1620 and read fromthe memory 1620. The speed is then used to control signals transmittedto the stepper motor drivers.

The I/O device(s) 1640 provides input and/or output interfaces for thesystem 1600. In some embodiments, the I/O device(s) 1640 include anetwork interface controller (NIC) that enables the system 1600 tocommunicate with other devices over a network, such as a local areanetwork (LAN) or a wide area network (WAN) such as the Internet. In someembodiments, the non-volatile storage 1630 can include both local andremote computer readable media. The remote computer readable media canrefer to a network storage device such as a storage area network (SAN)or a cloud-based storage service. The I/O device(s) 1640 can alsoinclude, but are not limited to, a serial communication device (e.g.,RS-232 port, USB host, etc.), a wireless interface device (e.g., atransceiver conforming to Wi-Fi or cellular communication protocols), asensor interface controller, a video controller (e.g., a graphics card),or the like.

It will be appreciated that the system 1600 is merely one exemplarycomputer architecture and that the control unit 139 or other processingdevices can include various modifications such as additional componentsin lieu of or in addition to the components shown in FIG. 16. Forexample, in some embodiments, the control unit 139 can be implemented asa system-on-chip (SoC) that includes a primary integrated circuit diecontaining one or more CPU core, one or more GPU cores, a memorymanagement unit, analog domain logic and the like coupled to a volatilememory such as one or more SDRAM integrated circuit dies stacked on topof the primary integrated circuit dies and connected via wire bonds,micro ball arrays, and the like in a single package (e.g., chip). Thechip can be included in a chipset that includes additional chipsproviding the I/O device 1640 functionality when connected to the SoCvia a printed circuit board.

FIG. 17 is a schematic illustration showing a dialysis system 1700 withwhich the smart dialysis bag detection system described herein may beutilized, according to an implementation of the present disclosure. Thesystem 1700 includes a dialysis machine 1702, which may be a PD machinelike the dialysis machine 102 discussed elsewhere herein for flowingfresh dialysate into a patient and draining used dialysate out of thepatient. One or more dialysate sources may be connected to the dialysismachine 1702. In some embodiments, as illustrated, the dialysatesource(s) may be dialysate bags 1710, 1711, 1712 that are disposed nearthe dialysis machine 1702. In an embodiment, the dialysate bags 1710,1711, 1712 may be hung which may improve air content management as anyair content is disposed by gravity to a top portion of the dialysate bag1710, 1711, 1712. Additionally and/or alternatively, the dialysate bags1710, 1711, 1712 may be disposed on shelves below or near the dialysismachine 1702. Valves may be attached to a bottom portion of thedialysate bags 1710, 1711, 1712 so fluid is drawn out and air contentdelivery is minimized.

The dialysate bags 1710, 1711, 1712 may be connected to a cassette 1715,which may be insertable into the dialysis machine 1702. In use, thecassette 1715 may be connected to dialysate bag lines of the dialysatebags 1710, 1711, 1712 with smart connectors 1720, 1721, 1722, which maybe used to pass dialysate from dialysate bags 1710, 1711, 1712 to thecassette 1715, and which may each have features like one or more of thesmart connectors discussed elsewhere herein, such as smart connector900. Although three dialysate bags 1710, 1711, 1712 and three smartconnectors 1720, 1721, 1722 are illustrated, the system described hereinmay be utilized in connection with more or fewer bags and/or connectors.In use, the cassette 1715 may be disposable. Alternatively, the cassette1715 may be reusable. In addition, a patient line and a drain line maybe connected or associated with the cassette 1715. The patient line maybe connected to the abdomen of a patient 1701 via a catheter and may beused to pass dialysate back and forth between the cassette 1715 and thepatient's peritoneal cavity during use. The drain line may be connectedto a drain or drain receptacle 1730 and may be used to pass dialysatefrom the cassette 1715 to the drain or drain receptacle 1730 during use.

As further described in detail elsewhere herein, information read fromtag(s) of the smart connectors 1710, 1711, 1712 by a reader can beutilized by a controller 1739 of the dialysis machine 1702, for example,a controller having features like the control unit 139 discussedelsewhere herein. In an embodiment, the smart connectors 1710, 1711,1712 enable the storing and reading of information that indicates aformulation or a volume of one or more of the dialysis bags 1710, 1711,1712 connected to the ports of the cassette 1715 such that the dialysismachine 1702 can automatically discover the configuration of thedialysis setup and/or make automatic changes. For example, byautomatically detecting the volume and/or concentration of one or moreof the dialysate bags 1710, 1711, 1712 connected to each port of thedisposable cassette 1715, the dialysis machine 1702 can determine when adialysis bag has been drained. As another example, different volumes ofdialysate from two or more different dialysate bags 1710, 1711, 1712with different concentrations of minerals or electrolytes can be mixedto create concentrations between the two source concentrations (e.g.,equal volume of 1.5% dextrose and 2.5% dextrose solutions can be mixedto create a 2.0% dextrose solution, or a 10% dextrose solution can bemixed with pure saline to produce a concentration between 0-10%).

The system and techniques described herein are discussed forillustrative purposes principally in connection with a particular typeof PD cycler, for example a PD cycler having piston-based pumps and aheater tray used to batch heat dialysate in a heater bag. It is notedthat the system and techniques described herein may be suitably used inconnection with other types and configurations of dialysis machinesand/or medical devices involving the transmission of fluid to and from apatient via a patient line and for which patient line checks andocclusion detection would be beneficially performed. For example, thesystem and techniques described herein may be used in connection with aPD cycler using a different configuration and style of pump, such as aperistaltic pump, and may be used in connection with other types ofdialysate heating arrangements, such as in-line heating arrangements.Further, the system described herein may be suitably used in connectionwith other types of dialysis machines, including, for example,hemodialysis machines.

It is noted that the techniques described herein may be embodied inexecutable instructions stored in a computer readable medium for use byor in connection with a processor-based instruction execution machine,system, apparatus, or device. It will be appreciated by those skilled inthe art that, for some embodiments, various types of computer-readablemedia can be included for storing data. As used herein, a“computer-readable medium” includes one or more of any suitable mediafor storing the executable instructions of a computer program such thatthe instruction execution machine, system, apparatus, or device may read(or fetch) the instructions from the computer-readable medium andexecute the instructions for carrying out the described embodiments.Suitable storage formats include one or more of an electronic, magnetic,optical, and electromagnetic format. A non-exhaustive list ofconventional exemplary computer-readable medium includes: a portablecomputer diskette; a random-access memory (RAM); a read-only memory(ROM); an erasable programmable read only memory (EPROM); a flash memorydevice; and optical storage devices, including a portable compact disc(CD), a portable digital video disc (DVD), and the like.

It should be understood that the arrangement of components illustratedin the attached Figures are for illustrative purposes and that otherarrangements are possible. For example, one or more of the elementsdescribed herein may be realized, in whole or in part, as an electronichardware component. Other elements may be implemented in software,hardware, or a combination of software and hardware. Moreover, some orall of these other elements may be combined, some may be omittedaltogether, and additional components may be added while still achievingthe functionality described herein. Thus, the subject matter describedherein may be embodied in many different variations, and all suchvariations are contemplated to be within the scope of the claims.

To facilitate an understanding of the subject matter described herein,many aspects are described in terms of sequences of actions. It will berecognized by those skilled in the art that the various actions may beperformed by specialized circuits or circuitry, by program instructionsbeing executed by one or more processors, or by a combination of both.The description herein of any sequence of actions is not intended toimply that the specific order described for performing that sequencemust be followed. All methods described herein may be performed in anysuitable order unless otherwise indicated herein or otherwise clearlycontradicted by context.

The use of the terms “a” and “an” and “the” and similar references inthe context of describing the subject matter (particularly in thecontext of the following claims) are to be construed to cover both thesingular and the plural, unless otherwise indicated herein or clearlycontradicted by context. The use of the term “at least one” followed bya list of one or more items (for example, “at least one of A and B”) isto be construed to mean one item selected from the listed items (A or B)or any combination of two or more of the listed items (A and B), unlessotherwise indicated herein or clearly contradicted by context.Furthermore, the foregoing description is for the purpose ofillustration only, and not for the purpose of limitation, as the scopeof protection sought is defined by the claims as set forth hereinaftertogether with any equivalents thereof. The use of any and all examples,or exemplary language (e.g., “such as”) provided herein, is intendedmerely to better illustrate the subject matter and does not pose alimitation on the scope of the subject matter unless otherwise claimed.The use of the term “based on” and other like phrases indicating acondition for bringing about a result, both in the claims and in thewritten description, is not intended to foreclose any other conditionsthat bring about that result. No language in the specification should beconstrued as indicating any non-claimed element as essential to thepractice of the invention as claimed.

What is claimed is:
 1. A dialysis system, comprising: a wirelessinterface in communication with one or more connectors attached to fluidlines; and a reader configured to access information stored in the oneor more connectors, wherein each connector of the one or more connectorsincludes a first portion and a second portion, and at least one of thefirst portion or the second portion includes a radio frequencyidentifier (RFID) device that is operational when the first portion ismated with the second portion and is not operational when the firstportion is disconnected from the second portion.
 2. The dialysis systemof claim 1, wherein the reader is a near field communication (NFC)device.
 3. The dialysis system of claim 2, wherein the NFC device isconfigured to: transmit a radio frequency (RF) signal over the wirelessinterface; and receive an RFID signal from a first connector of the oneor more connectors that includes a tag that indicates at least one of aformulation or a volume of a dialysis bag connected to a first fluidline fluidly coupled to the first connector.
 4. The dialysis system ofclaim 1, further comprising a disposable cassette that includes aplurality of ports, each port fluidly coupled to the second portion of acorresponding connector of the one or more connectors.
 5. The dialysissystem of claim 4, wherein the second portion includes an antenna of theRFID device and the first portion of the corresponding connector, whenmated to the second portion, includes an RFID chip.
 6. The dialysissystem of claim 4, wherein the second portion includes an interconnectconfigured to route a signal from a first terminal to a second terminal,and wherein the first portion of the corresponding connector, when matedto the second portion, includes an RFID chip and an antenna, and asignal interconnect from the RFID chip is connected to the firstterminal and the second terminal is connected to the antenna.
 7. Thedialysis system of claim 4, wherein the second portion includes a memorythat stores second information that identifies the port of thedisposable cassette fluidly connected to the corresponding connector,wherein the first portion of the corresponding connector, when mated tothe second portion, includes an RFID chip or a memory that stores firstinformation that indicates at least one of a formulation or a volume ofa dialysis bag, and wherein the RFID chip is configured to encode thefirst information and the second information to generate a tag that istransmitted to the reader.
 8. The dialysis system of claim 1, whereinthe second portion comprises a female connector that includes a taperedorifice.
 9. The dialysis system of claim 8, wherein the first portioncomprises a male connector that includes a protrusion that fits in thetapered orifice, and wherein the at least one component of the RFIDdevice is encapsulated in the first portion in accordance with anovermolding manufacturing process.
 10. A smart connector for a medicaldevice, wherein the smart connector comprises: a first portion thatincludes a radio frequency identifier (RFID) chip; and a second portionthat enables operation of the RFID chip when mated to the first portionand disables operation of the RFID chip when disconnected from the firstportion.
 11. The smart connector of claim 10, wherein the second portionincludes an antenna, and wherein a radio frequency (RF) signal receivedby the antenna causes the RFID chip to transmit, via the antenna, anRFID signal that includes a tag.
 12. The smart connector of claim 11,wherein the tag comprises one or more bits that encode informationcorresponding to at least one of a formulation or a volume of a dialysisbag connected to the first portion of the smart connector.
 13. The smartconnector of claim 10, wherein the first portion is a male connector andthe second portion is a female connector that includes a taperedorifice.
 14. The smart connector of claim 10, wherein the first portionfurther includes an antenna, and wherein an RFID signal generated by theRFID chip is routed through the second portion to the antenna.
 15. Thesmart connector of claim 10, wherein the second portion includes amemory that stores second information that identifies a port of adisposable cassette, wherein the first portion includes the RFID chip ora memory that stores first information that indicates at least one of aformulation or a volume of a dialysis bag, and wherein the RFID chip isconfigured to encode the first information and the second information togenerate a tag.
 16. A method for operating a dialysis machine, themethod comprising: transmitting, via a wireless interface, a radiofrequency (RF) signal; and receiving, via the wireless interface, atleast one tag corresponding to one or more connectors attached to fluidlines, wherein each connector of the one or more connectors includes afirst portion and a second portion, and at least one of the firstportion or the second portion includes a radio frequency identifier(RFID) device that is operational when the first portion is mated withthe second portion and is not operational when the first portion isdisconnected from the second portion.
 17. The method of claim 16,wherein an RFID signal from a first connector of the one or moreconnectors includes a tag that indicates at least one of a formulationor a volume of a dialysis bag connected to a first fluid line fluidlycoupled with the first connector.
 18. The method of claim 16, the methodfurther comprising: receiving prescription information related totreatment of a patient of the dialysis machine; comparing informationreceived from at least one connector of the one or more connectors tothe prescription information to determine whether at least one offormulation or volume of one or more dialysis bags connected to the oneor more connectors matches the prescription information; and initiatinga dialysis treatment when the information matches the prescriptioninformation, or setting an alarm when the information does not match theprescription information.
 19. The method of claim 16, the method furthercomprising: prompting a user to connect fluid lines to a disposablecassette; and transmitting, periodically, a radio frequency (RF) signalvia a wireless interface to poll the one or more connectors to receivetags that indicate when a first portion of each connector of the one ormore connectors is mated to a second portion of the connector.
 20. Themethod of claim 16, wherein a near field communication (NFC) devicereceives the at least one tag from the wireless interface and isconfigured to: compare the at least one tag to a history of stored tagsto determine if any of the tags in the at least one tag represent newlydiscovered connections.